But it's being criticised by the Church which claims it will leave babies with three parents.
It involves changing the defective part of a human cell, called the mitochondria.
What is Mitochondria?
Mitochondria is a tiny structure inside cells which generate the energy that allows our bodies to function.
It has its own DNA but it does not have any impact on a person's characteristics or appearance.
What is Mitochondrial disease?
Sometimes the Mitochondria inside the cell can mutate preventing it from working properly which causes a number of diseases, often life threatening.
It causes major problems to organs, can leave people blind, cause muscle wasting and eventual early death.
How is it passed onto children?
Children can only inherit mitochondrial DNA defects from their mothers, which means this technique, if approved, would give a child the DNA of a mother without the gene.
Often people are 'carriers' of the gene and will experience no symptoms.
How would Mitochondrial donation work?
The defective DNA from the mother's egg would be replaced by health Mitochondrial from a donor egg. That would stop the harmful genetics being passed onto children.
How safe is it?
So far animal and lab tests have shown it is safe but no one will say for sure there is zero risk.
It's not accurately known how much of an effect, if any, changing the mitochondrial DNA would have in a baby.